Nuclear Physics Data for Science and Technology
We investigate neutron-induced and photonuclear reactions to provide data relevant to basic science, nuclear astrophysics, and technology. For that purpose a neutron time-of-flight facility and a bremsstrahlung beam line were installed at the superconducting electron accelerator ELBE.
The nELBE neutron time-of-flight facility
Contact: Arnd Junghans
The nELBE neutron source is the world's only photo neutron source built at a superconducting electron accelerator. This combination enables a very precise time structure, high repetition rate and favourable background conditions.
The ELBE electron beam is focused onto a liquid lead circuit to produce neutrons in the energy range from below 100 keV to above 10 MeV. The temporal length of the electron bunches is in the order of a few pico seconds and the interaction volume has a size (width/length/height) of 11 x 11 x 5 mm3. Therefore the start point of the neutrons is well defined in space and time. The usable flight path can be selected between 5 to 11 m. Using particle detectors with a time resolution in the order of 1 ns enables a neutron energy resolution of about 1 % at 1 MeV kinetic energy.
The neutron source strength is about 1011 neutrons per second at the maximum electron bunch charge of 77 pC and a repetition rate of 100 kHz. This scales down to about 104 neutrons per second and square centimeter after a flight path of about 7 m.
A broad pool of neutron and photon detectors and data acquisition hardware for various types of experiments can be provided to interested users. The scientific standard program comprises measurements of total, elastic and inelastic scattering, and fission cross sections, the determination of photon angular distributions from inelastic scattering, as well as detector characterization experiments.
The γELBE bremsstrahlung facility
Contact: Ronald Schwengner
γELBE is the world's only facility producing bremsstrahlung γ-rays with energies greater than 10 MeV. This beam line offers a continuous spectrum of γ-rays with a maximum energy selectable between 6 and 18 MeV.
The bremsstrahlung is produced by shooting the ELBE electron beam through a thin niobium foil. A photon flux of about 109 s-1 is reached using a foil thickness of 12.5 µm at a typical electron current in the order of 500 µA.
An array of four high purity germanium detectors is installed and in routinely use to perform nuclear resonance fluoresence measurements to study electromagnetic strength functions.